ENG-2218 Copy one asset from Supabase into Roam storage

[maparent]

Reviewer brief

This is introducing a function that copies assets from firebase to supabase.
It is exercised in following PRs.

Verification

Unit tests.

Loom video

https://www.loom.com/share/244e8b7981434353b2407984c902a0f8

Scope check

• Ran $scope-check against the ENG ticket and final diff.
• Scope beyond Done When: extractUploadedUrl accepts two upload-return shapes beyond the five the ticket enumerates — the bracket-less {{pdf|audio|video: url}} embed and label — marked in code as tolerance, not observed returns.
• Required now: No ticket requires them. The argument is failure cost, not coverage: an unrecognised return throws after the bytes are already uploaded, orphaning a file in the user's storage and leaving the asset unresolved, and each retry orphans another. Every branch requires https?://, so the added tolerance cannot record a non-URL.
• Anyone affected or consulted: No. This was proposed by the review agent.
• Decision: Not documented — record the tolerance rationale in a Linear comment on ENG-2218 before merge; design.md Decision 4 documents the observed shapes only.

Local delegated full review

• Ran a comprehensive review of the entire final diff in a subagent with a fresh context. Use $dg-delegated-full-review when no other full-review workflow is available.

https://linear.app/discourse-graphs/issue/ENG-2218/copy-one-asset-from-supabase-into-roam-storage

[linear-code]

ENG-2218

[supabase]

This pull request has been ignored for the connected project zytfjzqyijgagqxrzbmz because there are no changes detected in packages/database/supabase directory. You can change this behaviour in Project Integrations Settings ↗︎.

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Project	Deployment	Actions	Updated
discourse-graph	Ready	Preview	Sep 10, 2026 8:47pm UTC

[graphite-app]

PR size/scope check

This PR is over our review-size guideline.

• Recommended: ~200 lines changed
• Acceptable limit: up to 400 lines when well-scoped/self-contained
• Preferred file count: fewer than 5 files

Please split this into smaller PRs unless there is a clear reason the changes need to land together.

If keeping it as one PR, please add a brief justification covering:

• What single problem this PR solves
• Why the files/changes are coupled

[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no bugs or issues to report.